1 /* $NetBSD: ext2fs_bmap.c,v 1.31 2023/08/26 05:22:50 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94
37 * Modified for ext2fs by Manuel Bouyer.
38 */
39
40 /*
41 * Copyright (c) 1997 Manuel Bouyer.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 *
52 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
53 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
54 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
55 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
56 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
57 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
58 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
59 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
60 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
61 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
62 *
63 * @(#)ufs_bmap.c 8.6 (Berkeley) 1/21/94
64 * Modified for ext2fs by Manuel Bouyer.
65 */
66
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: ext2fs_bmap.c,v 1.31 2023/08/26 05:22:50 riastradh Exp $");
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/buf.h>
73 #include <sys/proc.h>
74 #include <sys/vnode.h>
75 #include <sys/mount.h>
76 #include <sys/resourcevar.h>
77 #include <sys/trace.h>
78
79 #include <miscfs/specfs/specdev.h>
80
81 #include <ufs/ufs/inode.h>
82 #include <ufs/ufs/ufsmount.h>
83 #include <ufs/ufs/ufs_extern.h>
84 #include <ufs/ext2fs/ext2fs.h>
85 #include <ufs/ext2fs/ext2fs_extern.h>
86
87
88 static int ext4_bmapext(struct vnode *, int32_t, int64_t *, int *, int *);
89 static int ext2fs_bmaparray(struct vnode *, daddr_t, daddr_t *, struct indir *,
90 int *, int *);
91
92 #define is_sequential(ump, a, b) ((b) == (a) + ump->um_seqinc)
93
94 /*
95 * Bmap converts a the logical block number of a file to its physical block
96 * number on the disk. The conversion is done by using the logical block
97 * number to index into the array of block pointers described by the dinode.
98 */
99 int
ext2fs_bmap(void * v)100 ext2fs_bmap(void *v)
101 {
102 struct vop_bmap_args /* {
103 struct vnode *a_vp;
104 daddr_t a_bn;
105 struct vnode **a_vpp;
106 daddr_t *a_bnp;
107 int *a_runp;
108 } */ *ap = v;
109
110 /*
111 * Check for underlying vnode requests and ensure that logical
112 * to physical mapping is requested.
113 */
114 if (ap->a_vpp != NULL)
115 *ap->a_vpp = VTOI(ap->a_vp)->i_devvp;
116 if (ap->a_bnp == NULL)
117 return 0;
118
119 if (VTOI(ap->a_vp)->i_din.e2fs_din->e2di_flags & EXT2_EXTENTS)
120 return ext4_bmapext(ap->a_vp, ap->a_bn, ap->a_bnp,
121 ap->a_runp, NULL);
122 else
123 return ext2fs_bmaparray(ap->a_vp, ap->a_bn, ap->a_bnp, NULL,
124 NULL, ap->a_runp);
125 }
126
127 /*
128 * Convert the logical block number of a file to its physical block number
129 * on the disk within ext4 extents.
130 */
131 static int
ext4_bmapext(struct vnode * vp,int32_t bn,int64_t * bnp,int * runp,int * runb)132 ext4_bmapext(struct vnode *vp, int32_t bn, int64_t *bnp, int *runp, int *runb)
133 {
134 struct inode *ip;
135 struct m_ext2fs *fs;
136 struct ext4_extent *ep;
137 struct ext4_extent_path path = { .ep_bp = NULL };
138 daddr_t lbn;
139 int error = 0;
140
141 ip = VTOI(vp);
142 fs = ip->i_e2fs;
143 lbn = bn;
144
145 /* XXX: Should not initialize on error? */
146 if (runp != NULL)
147 *runp = 0;
148
149 if (runb != NULL)
150 *runb = 0;
151
152 ext4_ext_find_extent(fs, ip, lbn, &path);
153 if (path.ep_is_sparse) {
154 *bnp = -1;
155 if (runp != NULL)
156 *runp = path.ep_sparse_ext.e_len -
157 (lbn - path.ep_sparse_ext.e_blk) - 1;
158 if (runb != NULL)
159 *runb = lbn - path.ep_sparse_ext.e_blk;
160 } else {
161 if (path.ep_ext == NULL) {
162 error = EIO;
163 goto out;
164 }
165 ep = path.ep_ext;
166 *bnp = fsbtodb(fs, lbn - ep->e_blk
167 + (ep->e_start_lo | (daddr_t)ep->e_start_hi << 32));
168
169 if (*bnp == 0)
170 *bnp = -1;
171
172 if (runp != NULL)
173 *runp = ep->e_len - (lbn - ep->e_blk) - 1;
174 if (runb != NULL)
175 *runb = lbn - ep->e_blk;
176 }
177
178 out:
179 if (path.ep_bp != NULL) {
180 brelse(path.ep_bp, 0);
181 }
182
183 return error;
184 }
185
186
187
188 /*
189 * Indirect blocks are now on the vnode for the file. They are given negative
190 * logical block numbers. Indirect blocks are addressed by the negative
191 * address of the first data block to which they point. Double indirect blocks
192 * are addressed by one less than the address of the first indirect block to
193 * which they point. Triple indirect blocks are addressed by one less than
194 * the address of the first double indirect block to which they point.
195 *
196 * ext2fs_bmaparray does the bmap conversion, and if requested returns the
197 * array of logical blocks which must be traversed to get to a block.
198 * Each entry contains the offset into that block that gets you to the
199 * next block and the disk address of the block (if it is assigned).
200 */
201
202 int
ext2fs_bmaparray(struct vnode * vp,daddr_t bn,daddr_t * bnp,struct indir * ap,int * nump,int * runp)203 ext2fs_bmaparray(struct vnode *vp, daddr_t bn, daddr_t *bnp, struct indir *ap,
204 int *nump, int *runp)
205 {
206 struct inode *ip;
207 struct buf *bp, *cbp;
208 struct ufsmount *ump;
209 struct mount *mp;
210 struct indir a[EXT2FS_NIADDR+1], *xap;
211 daddr_t daddr;
212 daddr_t metalbn;
213 int error, maxrun = 0, num;
214
215 ip = VTOI(vp);
216 mp = vp->v_mount;
217 ump = ip->i_ump;
218 #ifdef DIAGNOSTIC
219 if ((ap != NULL && nump == NULL) || (ap == NULL && nump != NULL))
220 panic("ext2fs_bmaparray: invalid arguments");
221 #endif
222
223 if (runp) {
224 /*
225 * XXX
226 * If MAXBSIZE is the largest transfer the disks can handle,
227 * we probably want maxrun to be 1 block less so that we
228 * don't create a block larger than the device can handle.
229 */
230 *runp = 0;
231 maxrun = MAXBSIZE / mp->mnt_stat.f_iosize - 1;
232 }
233
234 if (bn >= 0 && bn < EXT2FS_NDADDR) {
235 /* XXX ondisk32 */
236 *bnp = blkptrtodb(ump, fs2h32(ip->i_e2fs_blocks[bn]));
237 if (*bnp == 0)
238 *bnp = -1;
239 else if (runp)
240 /* XXX ondisk32 */
241 for (++bn; bn < EXT2FS_NDADDR && *runp < maxrun &&
242 is_sequential(ump, (daddr_t)fs2h32(ip->i_e2fs_blocks[bn - 1]),
243 (daddr_t)fs2h32(ip->i_e2fs_blocks[bn]));
244 ++bn, ++*runp);
245 return 0;
246 }
247
248 xap = ap == NULL ? a : ap;
249 if (!nump)
250 nump = #
251 if ((error = ufs_getlbns(vp, bn, xap, nump)) != 0)
252 return error;
253
254 num = *nump;
255
256 /* Get disk address out of indirect block array */
257 /* XXX ondisk32 */
258 daddr = fs2h32(ip->i_e2fs_blocks[EXT2FS_NDADDR + xap->in_off]);
259
260 #ifdef DIAGNOSTIC
261 if (num > EXT2FS_NIADDR + 1 || num < 1) {
262 printf("ext2fs_bmaparray: num=%d\n", num);
263 panic("ext2fs_bmaparray: num");
264 }
265 #endif
266 for (bp = NULL, ++xap; --num; ++xap) {
267 /*
268 * Exit the loop if there is no disk address assigned yet and
269 * the indirect block isn't in the cache, or if we were
270 * looking for an indirect block and we've found it.
271 */
272
273 metalbn = xap->in_lbn;
274 if (metalbn == bn)
275 break;
276 if (daddr == 0) {
277 mutex_enter(&bufcache_lock);
278 cbp = incore(vp, metalbn);
279 mutex_exit(&bufcache_lock);
280 if (cbp == NULL)
281 break;
282 }
283 /*
284 * If we get here, we've either got the block in the cache
285 * or we have a disk address for it, go fetch it.
286 */
287 if (bp)
288 brelse(bp, 0);
289
290 xap->in_exists = 1;
291 bp = getblk(vp, metalbn, mp->mnt_stat.f_iosize, 0, 0);
292 if (bp == NULL) {
293
294 /*
295 * getblk() above returns NULL only iff we are
296 * pagedaemon. See the implementation of getblk
297 * for detail.
298 */
299
300 return ENOMEM;
301 }
302 if (bp->b_oflags & (BO_DONE | BO_DELWRI)) {
303 trace(TR_BREADHIT, pack(vp, size), metalbn);
304 }
305 #ifdef DIAGNOSTIC
306 else if (!daddr)
307 panic("ext2fs_bmaparry: indirect block not in cache");
308 #endif
309 else {
310 trace(TR_BREADMISS, pack(vp, size), metalbn);
311 bp->b_blkno = blkptrtodb(ump, daddr);
312 bp->b_flags |= B_READ;
313 VOP_STRATEGY(vp, bp);
314 curlwp->l_ru.ru_inblock++; /* XXX */
315 if ((error = biowait(bp)) != 0) {
316 brelse(bp, 0);
317 return error;
318 }
319 }
320
321 /* XXX ondisk32 */
322 daddr = fs2h32(((int32_t *)bp->b_data)[xap->in_off]);
323 if (num == 1 && daddr && runp)
324 /* XXX ondisk32 */
325 for (bn = xap->in_off + 1;
326 bn < MNINDIR(ump) && *runp < maxrun &&
327 is_sequential(ump, ((int32_t *)bp->b_data)[bn - 1],
328 ((int32_t *)bp->b_data)[bn]);
329 ++bn, ++*runp);
330 }
331 if (bp)
332 brelse(bp, 0);
333
334 daddr = blkptrtodb(ump, daddr);
335 *bnp = daddr == 0 ? -1 : daddr;
336 return 0;
337 }
338